Fertilization systems of sunflower and corn in relay intercropping

摘要

The relay intercropping, where a second crop is established after the first one has reached the reproductive stage of growth, is a system that reveal great potential use in small farms. However, to achieve a more efficient system, it is necessary to determine management practices more suitable to this system, such as date and manner of fertilizer application in both crops. This work was conducted in Eldorado do Sul, state of Rio Grande do Sul, Brazil, in the 1993/94 growing season. The objective ot these work was to compare the effect ot three tertilization systems in the relay intercropping of corn into suntiower. A early season and a late season corn cultivars were established in relay intercropping into sunflower. The fertilization systems were double row fertilization in sunflower, double broadcast fertilization in sunflower and individual row fertilization for sunflower and corn. The checks were two corn monocultures with individual row fertilization. Grain yield and yield components of sunflower crop were not affected by the fertilization systems tested. Sunflower biomass was 12.5% higher in double broadcast than in individual row fertilization system. Using double row fertilization in sunflower, the grain yield ot both com cultivars was similar to individual row fertilization in each crop. Differences were obtained between corn cultivars when double broadcast fertilization was used. The grain yield ot early season corn cultivar was lower than the grain yield of individual row fertilization, however, the grain yield of late season corn cultivar was similar.